There has been a persistent need to transport slurry materials through pipelines. Plain steel pipes were once commonly used for this purpose, but breakdown due to abrasion from the slurry material severely limited the functional lifetime of such a steel pipe. A breakthrough came with the introduction of a rubber liner in the steel pipe, which raised the functional lifetime of a steel pipe by around 500%. Rubber-lined steel became commonly used for pipelines in mining and energy development applications around the world.
However, rubber liners continue to involve persistent challenges, including expensive and problematic procedures to apply a rubber liner to a steel pipe, and significant deterioration over time of the rubber liner due to exposure to heat, hydrocarbons, and particulate matter.
New liners composed of materials such as polyurethane were introduced as an alternative to rubber liners. Polyurethane liners offered advantageous properties for resisting breakdown due to particulate matter. However, polyurethane liners also had significant performance drawbacks, including significant deterioration over time due to high levels of heat, and permeability to slurry transport fluid which often leads to blistering and disbondment of the liner from the pipe, a failure mode known as “cold wall effect”.
While no ideal pipeline liner solution has been available, the applications for liners have become ever more demanding, owing to the constant effort to develop new and often more challenging options in materials and energy resource extraction. For example, there is a growing interest in extracting energy resources from tar sands, which hold a tremendous potential for new energy development. However, extraction of energy resources from tar sands imposes harsh demands on equipment. Tar sands are typically extracted from the ground in a slurry including hydrocarbons, hot water, and particulate sand and rock material with particles up to four inches and greater in diameter.
Many types of traditional pipes and pipe liners have been applied in such tar sand applications, including rubber liners and polyurethane liners. However, under such extreme conditions, these liners quickly break down due to hydrocarbons, heat, abrasion by the particulate matter, and cold wall effect. Instead, the typical liner of choice in tar sand applications has become a hardened steel liner called chrome carbide overlay (CCO). CCO liners are extremely expensive and still have only marginal resistance to abrasion by the particulate matter. For example, typical CCO liners have been priced at several hundred dollars per foot, and have endured for only approximately three months of application in transporting tar sand slurry before failing and requiring replacement.
Therefore, there exists a substantial need for an improved solution for pipelines and other process support elements to transport or handle material under a wide range of conditions, such as those typically encountered in transporting tar sand slurries, for example.